Precision instrument



W. GAERTNER PRECISION INSTRUMENT Filed Dec. 51. 1-930 5N 1-EN TOR. M J

-B MI r-(LZZ MJ M/ A TTORNEYJE Feb. 28, 1933.

O\ .N. V Y M Patented Feb; 28; .1933

UNITED.STATES WILLIAMGAERTNER, crrrcaeo; rumors, "f

1 PRECISION mu s-m Thisinvention has to do with the means employed for manipulating the movable element of precision instruments in which deli-' v cate linear adjustments are.required,.and, in I numeral designates the bod t be of j a p telescope, within which is disposed a draw I tube 11,1snugly and slida-hly, fitting in spring-f sleeves 12,12a. 1 The body tube is threaded'on 5 'particular,.it provides an improvementfor i those devices iILWhiChZB, rack'and pinion are employed to impart the adjusting movements.

In microscopes, telescopes and other instruments in which focusing adjustments are required, a smooth, positive and precise adjustment of, the draw tube is essential to satisfactory use and it is of great importance that there be no failure in any of these respects.

'when such instruments are employed for scientific research and determinations.

Optical instruments ofjvarious kmdshave been provided with rack and pinion means for effecting focusing adjustmentsbut the o mounting and operation of such means have not compared favorably'with the minuteness of detailthat characterizes theconstruction' and assembly of the optical parts ofthe instrument. l

The principal objectof the. presentinvention is to provide an arrangement and mountinstrument or apparatus that will be firm, positive and permanent and still permit "of the most delicate of adjustments; Anotherobject is to improve the appearance of the device and to minimize the opportunity for even a slight disarrangement of theparts.

Other objects and advantages of the inven tion will become apparent upon reading the following specification andexamining the accompanying drawing of the improved ad 40 justing means as applied to ai-simpletelescope.

In the drawing,- Fig. 1 is an elevational' view of that side of the, telescope on which the adjustingmeans are mounted; a Fig. 2 is partly in elevation-and partly in a longitudinal section alongthe line 2 20f Fig.1; i

Fig. 3 is across sectionalview takenon the line 8-3 of Fig.2; and V v I Fig. is a cross sectional view on the line and th e draw -tuhe, fat its inner end, cargr es an eyepiece 14 which. is fitted friction 'tlghtther'em 1n the usual manner for smooth l l and longitudinal thereof is a rack 15. The sleeve .12a'1s slotted, asshownjin Fig. ,3,-to permit the .rackto pass therethrough. and to lee -Proof attachments thatwhen the. desired adjustment is attained i i of showing injdetfiil arrangement, assembly and mounting of the elements. I of'the ad usting means. I

i ;outer 1 nd to receive a telescope objective adjustment.

Secured to the oller W511 (lithe draw tube F6 form a guide for its longitudinal movement. At aboutthe. center of the body-tube, a por- .tion of ts Wall; sufficientto expose the rack o and to permit the; insertion of a pinion '16; for

engagement with the rack, iscutaway and replaced a transverse'bearing sleeve 17, haviingan opening in'the bottom thereof correspending to the shapeandsize of thecut I p away. portion of the body tube. The bearing ing of the means for manipulating the mov-- able element of a longitudinally adjustable soldering, brazing; welding or any other ineanstwhich will .aflord an unyielding and i The p1n1on16 is formed onia shaft'18," one.

of lwhich-isof reduced'diametere and is I inserted into an end cap 19, --which;cap:'is in friction?" tight engagement 1 with the corre- I spondng end of the bearing sleeve 17 and lim- I its'the endwise 'movementof'the shaft. The other end of the shaft'isof-slightlyreduced "diameter. and has fixedly securedthereto a e knurled head 20 which latter abuts but is \50 :rotatable on, the friction collar '21.

The intermediate portions of the pinion shaft 18 are in frictional engagement with j the innerwall of thebearing sleeve 17, withip; the result that a degreeof resistance is of fered'to manipulation of the head 20, thus insuring that any movement of the draw tube through the cooperation ofthe rack, pinion e and head will be positive and SInO0th.aI1d.1-Ij00 the parts will remain in their correct relative positions.

By attaching the bearing sleeve in a nonremovable manner and avoiding the use of screws in the assembly and mounting of the adjustment means, I provide a device that is capable of precise and steady manipulation throughout its life, is impervious to moisture,

is neat and sturdy and can be manufactured economically.

The invention is susceptible of a wide range of application. In addition to its usefulness for microscopes and telescopes, it

' may be employed to advantage in range finders and other military instruments, onele vating stands and, in fact, on any device in which a delicateylinear'movement of oneof the-parts is required.

I claim: c

1. Ina precision instrument, a draw tube having a rack mounted longitudinally thereon, a body tube embracing said draw tube 5 i and having an opening adjacent said rack,

a unitary bearing sleeve enclosing said opening and integral with saidbody tube, a shaft frictionally mounted in said sleeve, a pinion V rotated by said shaft and meshing with said rack, operating mechanism on one end oi said shaft and ialoutting the correspondin gr 7 end of said bearing sleeve, and a cap frictionally engaging the opposite {end of said shaft and said bearing sleeve.

2. In a precision instrument, a draw tube having a rack mounted longitudinally thereon, a body tube embracing said draw tube and having an opening adjacent said rack,

an extended unitary bearing sleeve integral with said body tube and enclosing saidopen- "ing therein, a rotatable shaft extending through said bearing sleeve and frictionally engaging the same, a pinion intermediate the ends of said shaft" and operatively connected to said rack, operating mechanism se- Q cured to one end of saidshaft and abutting saidbearing sleeve, and a push-fitlc ap engagf ing the other end of said shaft and abutting said bearing sleeve. 7

In testimony whereof I have'hereunto subscribed my name.

WILLIAM AERTNER; 

